In the darkness of the forest the young knight could hear the splashing of the fountain long before he could see the glimmer of moonlight reflected on the still surface. He was about to step forward, longing to dip his head, drink in the coolness, when he caught his breath at the sight of something dark, moving deep in the water. There was a greenish shadow in the sunken bowl of the fountain, something like a great fish, something like a drowned body. Then it moved and stood upright and he saw, frighteningly naked: a bathing woman. Her skin as she rose up, water coursing down her flanks, was even paler than the white marble bowl, her wet hair dark as a shadow.
She is Melusina, the water goddess, and she is found in hidden springs and waterfalls in any forest in Christendom, even in those as far away as Greece. She bathes in the Moorish fountains too. They know her by another name in the northern countries, where the lakes are glazed with ice and it crackles when she rises. A man may love her if he keeps her secret and lets her alone when she wants to bathe, and she may love him in return until he breaks his word, as men always do, and she sweeps him into the deeps, with her fishy tail, and turns his faithless blood to water.
The tragedy of Melusina, whatever language tells it, whatever tune it sings, is that a man will always promise more than he can do to a woman he cannot understand.
excerpt from The White Queen by Philippa Gregory